#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main()
{
	int sz = 0;
	double ave = 0;
	scanf("%d", &sz);
	double* score = malloc(sz);
	int i = 0;
	for (i = 0; i < sz; i++)
	{
		scanf("%lf", &score[i]);
		ave += score[i];
	}
	ave /= sz;
	printf("%.2f", ave);
	return 0;
}